Fission: HTTPTrigger admission omits RelativeURL / Prefix validation; kubectl apply bypasses CLI checks

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2026-50569: 0.23% estimated exploitation activity in the next 30 days; percentile 13.58 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

HTTPTriggerSpec.Validate() validated Methods, FunctionReference, Host, IngressConfig, and CorsConfig, but silently skipped RelativeURL and Prefix. Those two fields were validated at the CLI level only (pkg/fission-cli/cmd/httptrigger/create.go:83). The post-CRD-modernization webhook for HTTPTrigger was retired in favor of API-server CEL — and CEL had no rules on those fields either — so an HTTPTrigger created via kubectl apply or a direct Kubernetes REST API call bypassed every URL-level check. A tenant with HTTPTrigger create permission could therefore create triggers whose RelativeURL or Prefix: - was empty (with both fields unset, the trigger has no URL), - did not start with /, - was exactly / (claiming the entire router root), - contained .. traversal segments (e.g. /api/../admin), - collided with router-owned routes: /router-healthz, /readyz, /version, /auth/login, - collided with the router-internal function prefix /fission-function/<ns/<name. Affected - Project:…

Published by the source

28 Jul 2026, 20:16 UTC

Last modified by the source

18 Aug 2026, 15:00 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vchh-r53j-8mpw

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6131

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-vchh-r53j-8mpw

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-50569

Advisory: Fission: HTTPTrigger admission omits RelativeURL / Prefix validation; kubectl apply bypasses CLI checks
IDs: CVE-2026-50569, GHSA-vchh-r53j-8mpw
Record: https://patchnext.com/advisories/cve-2026-50569 (revision 3, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/fission/fission 1.25.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/fission/fission: affected <= 1.24.0; fixed in 1.25.0

## Suggested inspection (read-only)
- Go github.com/fission/fission: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/fission/fission.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-vchh-r53j-8mpw (OSV record GHSA-vchh-r53j-8mpw lists affected ranges: Go github.com/fission/fission >=0 <1.25.0 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6131 (OSV record GO-2026-6131 lists affected ranges: Go github.com/fission/fission >=0 <1.25.0 (fixed))
- Verified: https://github.com/advisories/GHSA-vchh-r53j-8mpw (GitHub-reviewed advisory GHSA-vchh-r53j-8mpw lists affected ranges: Go github.com/fission/fission >=0 <=1.24.0)

Commands are suggestions: review each one before running it.